Amplifier



FIG. 1 is a top view of the amplifier;

FIG. 2 is a left side view of the amplifier;

FIG. 3 is a front view of the amplifier;

FIG. 4 is a rear view of the amplifier;

FIG. 5 is a left-front perspective view of the amplifier; and,

FIG. 6 is a right-rear perspective view of the amplifier.

The bottom, not shown, is disclaimed.

The ornamental design for amplifier, as shown and described.